A trusted system is like having a really good and responsible friend. It's a computer or a network that you can trust to keep your information safe, just like you trust your responsible friend to keep your secrets safe.
Imagine that you have a secret password that you use to log into your favorite website. You don't want anyone else to know that password, right? Well, you can trust a trusted system to keep that password safe and protected, just like you can trust your responsible friend to keep your secret safe and not share it with anyone else.
A trusted system is designed to protect your information from bad guys who might try to steal it or use it for harm. Just like your responsible friend will protect your secrets from bad guys who might try to hurt you or use your secrets against you.
So when you use a trusted system, you can be confident that your information is being kept safe and that you can use the system to do things like online banking or shopping without worrying that bad guys will steal your information. Just like you can be confident that your responsible friend won't share your secrets with anyone who might hurt you.